Interconnect yield/reliability screening is necessary for fast turnaround time in process development and qualification. These interconnect yield/reliability screenings can be used for detecting pre-existing voiding, via bottom defects, metal fill issues, etc.
Voiding can be the result of electromigration effects, e.g., via depletion and line depletion. For example, electromigration is the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applications where high direct current densities are used, such as in microelectronics and related structures. As the structure size in electronics such as integrated circuits (ICs) decreases, the practical significance of this effect increases to the point of device failure.
However, current interconnect yield/reliability screening cannot detect weakness or marginal defects, particularly related to electromigration (EM) issues. Also, process development cycle is significantly limited by module-level long-term electromigration (EM) stresses with slow turnaround time.